Apparatus and method for tibial fixation of soft tissue

ABSTRACT

An apparatus and method for tibial fixation of a soft tissue graft includes a body having a first side and a second side. A first plurality of spikes extend from the second side of the body each having a first length. A second plurality of spikes extend from the second side of the body each having a second length where the first length is longer than the second length. The first plurality of spikes are operable to engage the bone without the second plurality of spikes substantially engaging the soft tissue graft to permit proper tensioning of the soft tissue graft. The method includes forming a tunnel in a bone and forming a counterbore substantially perpendicular with the tunnel. The soft tissue graft passes through the tunnel and the counterbore and is secured within the counterbore with an apparatus which is nested within the counterbore.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. Ser. No.09/356,959, filed on Jul. 19, 1999, entitled “APPARATUS AND METHOD FORTIBIAL FIXATION OF SOFT TISSUE, which is now U.S. Pat. No. 6,280,472,which is a continuation-in-part application of Ser. No. 08/900,602,filed Jul. 23, 1997, entitled “APPARATUS AND METHOD FOR ENDOSCOPICTIBIAL FIXATION OF SOFT TISSUE,”, which is now U.S. Pat. No. 5,931,869,issued Aug. 3, 1999.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to an apparatus and method for use inorthopedic surgery and, more particularly, to an apparatus and methodfor tibial fixation of a soft tissue graft through a tibial tunnel.

2. Discussion of the Related Art

Ligaments are strong fibrous connective soft tissue which connect thearticular ends of bones to bind them together and to facilitate or limitmotion. Injuries to ligaments are common, and patients who arephysically active are generally more susceptible to such ligamentinjuries. The anterior cruciate ligament (ACL) of the knee joint is aligament frequently injured by such patients. Such injuries causeinstability in the knee joint which, when left untreated, may lead todegenerative arthritis. Because of this condition, ACL reconstructionmay be required. Generally during ACL reconstruction, a substitute softtissue ligament or graft is attached to the femur and/or tibia tofacilitate regrowth and permanent attachment.

One method of performing this reconstruction involves the use of asection of bone-patellar tendon-bone as a graft. With this method, aligament tunnel is bored into both the femur and the tibia and thebone-patellar tendon-bone graft is centered between the tunnel. The boneportions of the graft are then each secured within the respective tunnelby tightening an interference screw in each tunnel between the bonegraft and the side of the tunnel.

However, use of such a technique presents several disadvantages. Forexample, the graft may be inadvertently cut or frayed by the sharp edgesof the interference screw during insertion of the screw and subsequentto fixation. Moreover, if the interference screw or the bone graft isslightly oversized versus the size of the tunnel, the interference screwmay cause too much force to be exerted on the bone graft portion as theinterference screw is tightened. This may subsequently cause the bonegraft portion to be damaged and not usable. In addition, it is oftendifficult to accurately gauge the length of the bone-patellartendon-bone graft in relation to the ligament tunnels such that the bonegraft portions may not seat appropriately within the tunnels or beproperly tensioned.

Another method for performing this reconstruction involves the use ofonly a soft tissue ligament graft. Such a graft is generally taken fromthe hamstring ligament, specifically, the semitendinosus and gracilisligaments or tendons. Such grafts are generally fed through the ligamenttunnel and secured outside the tunnel. The graft is generally secured bya non-endoscopic means of stapling or screwing the graft onto theoutside surface of the tibia and/or femur.

However, this method of securing the soft tissue graft also exhibitsdisadvantages. For example, since the various staple or screw and washerassemblies in existence are positioned on the outside of the bonesurface or extend beyond the bone surface, such components are moreeasily noticed by the patient and in some instances may cause patientdiscomfort. In addition, because of the discomfort, it may be requiredto perform subsequent surgery to remove the staple or screw and washerassembly once the graft has permanently attached to the bone, therebysubjecting the patient to a second surgery, as well as increasingoverall surgical costs. The staple or screw and washer assembly are alsonot substantially resistant to slippage and do not provide stiffsecurement. In other words, the graft may permanently slip under thesecurement of the staple or screw and washer assembly thereby providinga non-optimum tension on the graft. Securement at the anchoring pointmay be resilient such that if the graft utilizes sutures in combinationwith the staple or screw washer assembly, the anchoring point maystretch under stress and resiliently return, thereby also providingnon-optimum tensioning or stiffness for the graft.

Another method for securing the soft tissue ligament graft within afemoral tunnel is set forth in U.S. Pat. No. 5,431,651. This referenceuses a cleated washer which engages the soft tissue graft within thefemoral tunnel by use of a transverse cannulated set screw. The cleatedwasher is drawn into the femoral tunnel by use of a suture coupled tothe washer and pulled through the cannulated set screw. Once in positionadjacent to the set screw, the set screw engages the cleated washeragainst the soft tissue ligament and the wall of the tunnel.

However, this method of securing a soft tissue graft within a femoraltunnel also exhibits many disadvantages. For example, such a procedurewill generally require more surgical time since it includes the addedsteps of passing a suture through a cannulated set screw and down thefemoral tunnel, as well as attaching it to the cleated washer itself.This also makes it extremely difficult to properly align the cleatedwasher since the cleated washer must be pulled through and aligned usinga flexible non-rigid suture. Additionally, it may be difficult tomaintain the location of the cleated washer as the set screw is engagedagainst the washer since the suture does not rigidly hold or maintainthe position of the cleated washer. Finally, by drawing the cleatedwasher up through the femoral tunnel, a larger femoral tunnel may berequired and the spikes on the cleated washer may cut or fray the softtissue graft as it is passed through the femoral tunnel.

What is needed then is an apparatus and method for tibial fixation of asoft tissue graft which does not suffer from the above-identifieddisadvantages. This in turn, will reduce the possibility for damagingthe soft tissue graft; reduce the possibility for requiring a new graftfrom being harvested; provide for endoscopic securement of a soft tissuegraft without damaging the graft; reduce or eliminate potential patientdiscomfort; provide endoscopic fixation which is flush to the bonesurface; reduce or eliminate the need for a subsequent surgery to removefixation components after the graft has been permanently attached to thebone; provide increased fixation strength; provide less pretensioning ofthe graft to restore knee stability, thereby not over-constraining theknee after setting the tension on the graft; reduce or eliminate thepotential for slippage of the soft tissue graft; increase stiffness andmechanical behavior of the soft tissue graft; reduce the number of stepsto secure the soft tissue graft; and reduce the number of separateinstrumentation required to secure the soft tissue grafts. It is,therefore, an object of the present invention to provide such anapparatus and method for tibial fixation of a soft tissue graft.

SUMMARY OF THE INVENTION

In accordance with the teachings of the present invention, an apparatusand method for tibial fixation of a soft tissue graft is disclosed. Theapparatus and method flushly secures the soft tissue graft within atunnel formed in the tibia. This is basically achieved by utilizing anapparatus which does not extend beyond the tibia upon securing the graftwithin a tibial tunnel.

In one preferred embodiment, an apparatus for fixation of a soft tissuegraft includes a body having a first side and a second side. A firstplurality of spikes extend from the second side of the body each havinga first length. A second plurality of spikes extend from the second sideof the body each having a second length. The first length is longer thanthe second length such that the first plurality of spikes are operableto engage the bone without the second plurality of spikes substantiallyengaging the soft tissue graft to permit proper tensioning of the softtissue graft.

In another preferred embodiment, an apparatus for fixation of a softtissue graft within a counterbore formed into the bone includes a bodyhaving a first and second side. The body includes a substantiallycylindrical sidewall and a substantially planar relief formed into aportion of the cylindrical sidewall. A plurality of spikes extend fromthe second side of the body and are operable to engage the bone. Thesubstantially planar relief is operable to permit the body to be flushlyreceived within the counterbore and permit the soft tissue graft to exitthe counterbore without substantially binding on the cylindricalsidewall and the counterbore.

In another preferred embodiment, an apparatus for fixation of a softtissue graft within a tunnel formed in a bone includes a wedge having afirst side and a second side. The first side includes a plurality ofteeth which are operable to engage the soft tissue graft against thetunnel. The second side includes a threaded face operable to axiallyreceive an interference screw. Means are provided for preventing thewedge from axially extending into the tunnel more than a predeterminedamount.

In another preferred embodiment, a method for fixation of a soft tissuegraft includes forming a tunnel in a bone having an entrance opening.Forming a counterbore substantially perpendicular with the tunnel andpartially within the entrance opening. Passing a soft tissue graftthrough the tunnel along the counterbore. Securing the soft tissue graftwithin the counterbore with an apparatus which is nested within thecounterbore.

In another preferred embodiment, a method for fixation of a soft tissuegraft includes forming a tunnel in a bone. Forming a pilot hole adjacentto an entrance opening of the tunnel. Forming a counterboresubstantially concentric with the pilot hole and partially within theentrance opening. Passing a soft tissue graft through the tunnel alongthe counterbore. Securing the soft tissue graft within the counterborewith an apparatus which is flushly received within the counterbore.

In yet another preferred embodiment, a method for fixation of a softtissue graft in a bone includes forming a tunnel in the bone. Forming aguide bore substantially perpendicular to the tunnel. Forming acounterbore substantially perpendicular to the tunnel by use of theguide bore. Passing a graft into the tunnel and along the counterboreand securing the graft within the counterbore.

In another preferred embodiment, a method for fixation of a soft tissuegraft in a bone with a fixation apparatus includes forming a tunnel inthe bone. Forming a counterbore extending into the tunnel. Providing acombination implant and guide instrument. Passing the graft into thetunnel and along the counterbore. Implanting the fixation apparatuswithin the counterbore by use of a combination implant and guideinstrument to secure the graft within the tunnel. Guiding a drill bitwith the combination implant and guide instrument to form a borerelative to the tunnel. Passing a fixation screw through the fixationapparatus and into the bore to firmly secure the graft within thetunnel.

In a further preferred embodiment, a method for fixation of a softtissue graft in a bone includes forming a tunnel in the bone. Slidablyinserting a counterbore guide into the tunnel having a guide bushingsubstantially perpendicular to the tunnel. Forming a guide boresubstantially perpendicular to the tunnel by use of the guide bushing.Forming a counterbore substantially perpendicular to the tunnel by useof the guide bore. Passing the graft into the tunnel and along thecounterbore and securing the graft within the counterbore.

Use of the present invention provides an apparatus and method for tibialfixation of a soft tissue graft. As a result, the aforementioneddisadvantages associated with the currently available methods andtechniques for fixation of soft tissue grafts have been substantiallyreduced or eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS

Still other advantages of the present invention will become apparent tothose skilled in the art after reading the following specification byreference to the drawings in which:

FIG. 1 is a side view of an apparatus for tibial fixation of a softtissue graft according to the teachings of the present invention;

FIG. 2 is a top view of the tibial fixation apparatus of FIG. 1;

FIG. 3 is a side cross-sectional view of the tibial fixation apparatusof FIG. 1 taken along line 3—3 of FIG. 2;

FIG. 4 is a top view of a counterbore drill guide used in preparing acounterbore to nestingly receive the tibial fixation apparatus of FIG.1;

FIGS. 5A-5E illustrates a method for attaching a soft tissue graft usingthe tibial fixation apparatus according to the teachings of the presentinvention;

FIGS. 6A-6E illustrates another method for attaching a soft tissue graftusing the tibial fixation apparatus according to the teachings of thepresent invention;

FIG. 7 is a top view of another apparatus for tibial fixation of a softtissue graft according to the teachings of the present invention;

FIG. 8 is a bottom view of the tibial fixation apparatus of FIG. 7;

FIG. 9 is a front view of the tibial fixation apparatus of FIG. 7;

FIG. 10 is a side cross-sectional view of the tibial fixation apparatusof FIG. 7 taken along line 10—10 of FIG. 7;

FIG. 11 is a perspective view illustrating a method for positioning thetibial fixation apparatus of FIG. 7;

FIG. 12 is a side cross-sectional view taken along line 12—12 of FIG. 11illustrating the method for positioning the tibial fixation apparatus ofFIG. 7;

FIG. 13 is a top-end view of another apparatus for tibial fixation of asoft tissue graft according to the teachings of the present invention;

FIG. 14 is a bottom-end view of a tibial fixation apparatus of FIG. 13;

FIG. 15 is a side-end view of the tibial fixation apparatus of FIG. 13;

FIG. 16 is a top view of an instrument utilized for grasping the tibialfixation apparatus of FIG. 13;

FIG. 17 is a side cross-sectional view illustrating a method forpositioning the tibial fixation apparatus of FIG. 13 employing theinstrument of FIG. 16;

FIG. 18 is a side cross-sectional view of a tibial fixation apparatusaccording to the teachings of the preferred embodiment of the presentinvention;

FIG. 19 is a perspective view of a counterbore guide used in preparing acounterbore to nestingly receive the tibial fixation apparatus of FIG.18;

FIG. 20 is an elevational view of a first portion of a multi-purposeinstrument;

FIG. 21 is an elevational view of a second portion of the multi-purposeinstrument of FIG. 20;

FIGS. 22A-22D illustrates a first preferred method for attaching a softtissue graft using the tibial fixation apparatus according to theteachings of the preferred embodiment of the present invention;

FIG. 23 is a perspective view of another counterbore guide used inpreparing a counterbore to nestingly receive the tibial fixationapparatus of FIG. 18;

FIG. 24 is an elevational view of another multi-purpose instrument; and

FIGS. 25A-25C illustrates a second preferred method for attaching a softtissue graft using the tibial fixation apparatus according to theteachings of the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The following description of the preferred embodiments concerning anapparatus and method for tibial fixation of soft tissue grafts aremerely exemplary in nature and are in no way intended to limit theinvention or its application or uses. Moreover, while the presentinvention is described in detail below with reference to tibial fixationof soft tissue grafts through a tibial tunnel, it will be appreciated bythose skilled in the art that the present invention is clearly notlimited to fixation in a tibial tunnel and may be utilized to securesoft tissue grafts, tendons, ligaments, etc. in various other tunnels,bores or adjacent to a bone.

Referring to FIGS. 1-3, an apparatus 10 for tibial fixation of a softtissue graft according to the teachings of one embodiment of the presentinvention is shown. The apparatus or washer 10 includes a cylindricalbody 12 having a diameter of about 16 millimeters and a plurality ofspikes 14. The cylindrical body 12 includes a substantially cylindricalsidewall 16 having beveled or rounded edges 18 and a substantially flatplanar relief face 20 formed into a portion of the cylindrical sidewall16. The body 12 further defines a concentric internal bore 22 having aninternal sidewall 24 with a diameter of about 0.234 inches which isadapted to receive a compression bone screw, further discussed herein. Afirst side or top 26 of the body 12 includes a concentric counterbore 28operable to flushly receive a head of the compression screw. A secondside or bottom 30 of the body 12 is substantially planar and has theplurality of spikes 14 extending out from the second side 30.

The plurality of spikes 14 includes a first plurality or fourcylindrical guide spikes 32 each having a length from the top 26 of thebody 12 to the tip 34 of the spikes 32 of about 0.52 inches and acylindrical diameter of about 0.062 inches. The four spikes 32 arepositioned concentrically about the body 12 at a radius of about 0.25inches from the center of the body 12. The plurality of spikes 14further includes a second plurality or thirteen cylindrical engagementspikes 36 each having a length from the top 26 of the body 12 to the tip34 of the spikes 36 of about 0.34 inches and a cylindrical diameter ofabout 0.047 inches. The cylindrical spikes 32 and 36 each include thepointed end 34 operable to engage and penetrate cancellous and corticalbone. The engagement spikes 36 are positioned between the guide spikes32 and the internal bore 22 in such a manner that the engagement spikes36 are able to penetrate and secure the soft tissue graft at multiplesites, further discussed herein.

The apparatus or washer 10 is preferably made from a suitablebiocompatible material such as titanium, stainless steel, titaniumalloy, cobalt-chrome-molybdenum alloy, polymer, resorbable polymer, etc.The apparatus 10 preferably consists of an assembly of separate spikes14 which are welded to the body 12, via welds 38. Alternatively, theapparatus 10 may be cast or machined to the required shape and size.

Referring to FIG. 4, a counterbore drill guide 40 is shown for use inpreparation of a substantially perpendicular counterbore relative to atibial tunnel formed in a tibia, further discussed herein. Thecounterbore drill guide 40 includes a substantially cylindrical body 42defining a planar notched region 44 having a center aperture 46 forreceipt of a counterbore drill bit. Positioned adjacent to the notchedregion 44 is a positioning bar 48 passing medially through the body 42.The positioning bar 48 is slidably engaged with the body 42 and isutilized to engage the medial cortex of the tibia to provide apredetermined insertion length of the counterbore drill guide 40 intothe tibial tunnel. Set back from the positioning bar 48 is a T-shapedhandle 50 which can be utilized by the surgeon to hold the counterboredrill guide 40 during counterbore drilling. The body 42 of thecounterbore drill guide 40 is about 7 millimeters in diameter, with thenotched region 44 beginning at about 20 millimeters from a distal end ofthe drill guide 40. The notched region 44 is about 17 millimeters widehaving about a 3.5 millimeter diameter centering hole 46. Thepositioning bar 48 is set back about 10 millimeters from the center ofthe centering hole 46, thereby providing a predetermined insertionlength within the tibial tunnel of about 38.5 millimeters. Thecounterbore drill guide 40 is preferably made from stainless steel orother suitable material.

Turning to FIGS. 5A-5E, one method for tibial fixation of a soft tissuegraft will now be described. Initially, soft tissue grafts are harvestedfor use in an intrarticular cruciate ligament (ACL) reconstruction. Thesemitendinosus and gracilis tendons from their respective hamstringmuscles are generally used and harvested from the patient or by way ofdonor tendons using techniques well known in the art. Alternatively,synthetic grafts may also be employed. The harvested grafts willgenerally consist of two tubular grafts which are subsequently looped attheir mid-section to form a four bundle graft. The four bundle graftshould be sized to pass without friction through a tibial and femoraltunnel.

Once the grafts have been harvested and prepared using known techniques,tunnel or hole placement is then performed. A tibial tunnel or bore 52is drilled through the tibia 54 and into the femur 56 creating a femoraltunnel 58. The tibial tunnel 52 will typically have a diameter betweenabout 7 to 13 millimeters, preferably 8-9 millimeters, and is boredutilizing a drill bit and a driver. The tibial tunnel 52 exits at aboutthe center of the tibial plateau and enters the tibia 54 at about 50millimeters from the top of the tibial plateau medial to the tibialtubercle or at the medial cortex. Since the tibial tunnel 52 anglesthrough the tibia 54, it creates an elliptical entrance opening 60 andan elliptical exit opening 62. The drill bit utilized to bore the tibialtunnel 52 also generally bores the femoral tunnel 58 in the femur 56 bycontinuing to extend the drill bit through the tibial tunnel 52 and intothe femur 56. The tibial tunnel 52 and the femoral tunnel 58 are boredusing techniques well known in the art which may include the use ofalignment or drill guide mechanisms in combination with a drill bit anddriver.

Once the tibial tunnel 52 is bored through the tibia 54, the body 42 ofthe counterbore drill guide 40 is axially slid into the entrance opening60 of the tibial tunnel 52. The counterbore drill guide 40 is advancedinto the tibial tunnel 52 until the positioning bar 48 is flush againstthe medial cortex of the tibia 54. This will align the centering hole 46adjacent to an anterior edge 64 of the entrance opening 60 of the tibialtunnel 52.

With the counterbore drill guide 40 properly positioned within thetibial tunnel 52 and held by the handle 50, a counterbore 66 is formedsubstantially perpendicular to the tibial tunnel 52 using a counterborebit 68 and a drive mechanism 70. The counterbore bit 68 includes acentering nose 72 which rotatably engages the centering hole 46 formedinto the counterbore drill guide 40. The centering nose 72 is formedsimilar to a drill bit so that the centering nose 72 drills into thetibia 54. The counterbore 66 is preferably bored to remove the anterioredge 64 of the entrance opening 60 providing a substantiallyperpendicular counterbore 66. In other words, the centering nose 72 isdirected through the tibia 54 and inserted in the centering hole 46 inthe counterbore drill guide 40 such that the counterbore bit 68 isperpendicular to a posterior wall 74 of the tibial tunnel 52. Thecounterbore bit 68 is advanced to remove the anterior tibial cortexadjacent to an anterior wall 76 until it seats in the notch region 44 inthe counterbore drill guide 40. The bone reamings may then be collectedand saved for subsequent grafting of the tibial tunnel 52.

Once the counterbore 66 has been formed utilizing the counterbore bit68, a four bundle graft 78 is first secured within the femoral tunnel 58of the femur 56 using one of many techniques known in the art.Preferably, the four bundle graft 78 is secured within the femoraltunnel 58 of the femur 56 by means of a bone mulch screw, set forth inU.S. Pat. No. 5,674,224, “BONE MULCH SCREW ASSEMBLY FOR ENDOSTEALFIXATION OF SOFT TISSUE GRAFTS AND METHOD FOR USING SAME”, which ishereby incorporated by reference. With the graft 78 secured within thefemoral tunnel 58, the graft 78 extends out through the tibial tunnel52.

The apparatus 10 is then engaged and secured to the tibia 54 by use ofan impactor 80 in combination with a mallet. The impactor 80 has agenerally cylindrical body 82 which tapers to a striking end 84. Theimpactor 80 includes a complimentary face 86 having a concentric guidepost 88 which is received within the internal bore 22 and an arcuatesurface 90 which is received within the counterbore 28. The impactor 80further includes an edge guide 92 which engages and mates with theplanar relief face 20 formed within the apparatus 10. The edge guide 92enables the surgeon to properly rotatably align the apparatus 10 bysimply rotating the impactor 80 within the counterbore 66 and engagingthe planer face 20 with the edge guide 92.

The graft 78 is oriented such that two grafts 94 and 96 of the fourbundle graft 78 pass along a first side of the guide post 88 and twografts 98 and 100 pass along a second side the guide post 88 such thateach pair of grafts are positioned or guided between the guide post 88and the longer guide spikes 32. The apparatus 10 is initially partiallyengaged with only the guide spikes 32 penetrating cancellous andcortical bone of the tibia 54 and the relief face 20 directed toward theentrance opening 60. With the guide spikes 32 engaging the tibia 54, thefour bundle graft 78 is appropriately tensioned by pulling the fourbundle graft 78 under the engagement spikes 36 within the counterbore 66and out of an area 102 defined by the relief 20 and the counterbore 66without binding on the sidewall 16 or the counterbore 66. The two stagespikes 14 having the first plurality of spikes 32 of a first length andthe second plurality of spikes 36 having a second shorter length enablesthe apparatus 10 to be initially secured to the tibia 54 with only thespikes 32, while allowing proper tensioning and guiding of the fourbundle graft 78.

The four bundle graft 78 is properly tensioned generally by means ofpulling on the ends of the graft 78 extending out of the area 102 underthe relief 20 manually or with a tensioning device with the knee in fullextension. A preferred tensioning device is set forth in U.S. Pat. No.5,507,750 entitled, “METHOD AND APPARATUS FOR TENSIONING GRAFTS ANDLIGAMENTS”, which is hereby incorporated by reference. Once the propertension is achieved, the apparatus 10 is fully seated or nested withinthe counterbore 66 by use of the impactor 80 and a mallet, as shownclearly in FIG. 5C. Upon seating the apparatus 10, the engagement spikes36 penetrate the two grafts 94 and 96 on the first side of the guidepost 88 at multiple sites and the two grafts 98 and 100 on the secondside of the guide post 88 to maintain proper tensioning of the fourbundle graft 78. The apparatus or washer 10 thus seats or nests flushwithin the counterbore 66 thereby eliminating any objects extending outbeyond the tibia 54. The relief 20 is also used to eliminate any portionof the apparatus 10 from extending out beyond the tibia 54.

With the apparatus 10 fully nested within the counterbore 66 orposterior wall 74 of the tibia tunnel 52, a drill guide 101 is insertedinto the internal bore 22 of the apparatus 10 to maintain the separationof the four bundle graft 78. The drill guide 101 is advanced between thetwo grafts 94 and 96 on the first side of the guide post 88 and the twografts 98 and 100 on the second side of the guide post 88 so that it isflush against the posterior wall 74 of the tibial tunnel 52. A 3.5millimeter drill bit 104 attached to the driver 70 is then utilized todrill a bore 106 through the tibia 54 to the posterior cortex of thetibia 54. Once the bore 106 is drilled through the tibia 54, the depthof the bore 106 is measured and the posterior cortex region is tappedusing an appropriate tap.

With the bore 106 formed and tapped, a low profile compression screw 108is inserted into the internal bore 22 and screwed into the bore 106 inthe tibia 54 to threadably secure the compression screw 108 within thebore 106 and complete the fixation of the apparatus 10 within thecounterbore 66. The compression screw 108 includes a head 110 which isflushly received within the counterbore 28, a threaded section 112, anda cylindrical non-threaded section 114 passing through the body 12 ofthe apparatus 10. Once the compression screw 108 has been fully secured,the ends of the grafts 94-100 may be trimmed back within the area 102.The apparatus 10 provides a substantially stiff and slippage freeanchoring for the graft 78.

Turning to FIGS. 6A-6E, another method for tibial fixation of a softtissue graft will now be described. In this regard, like referencenumerals will be used to reference to like structures. Once the graftshave been harvested and prepared using the known techniques, tunnel orhole placement is again performed. The tibial tunnel or bore 52 isdrilled through the tibia 54 and into the femur 56 creating a femoraltunnel 58. The tibial tunnel 52 will typically have a diameter betweenabout 7 to 13 millimeters, preferably 8-9 millimeters, and is boredutilizing a drill bit and a driver. The tibial tunnel 52 exits at aboutthe center of the tibial plateau and enters the tibia 54 at about 50millimeters from the top of the tibial plateau medial to the tibialtubercle or at the medial cortex. Since the tibial tunnel 52 anglesthrough the tibia 54, it creates an elliptical entrance opening 60 andan elliptical exit opening 62. The drill bit utilized to bore the tibialtunnel 52 also generally bores the femoral tunnel 58 in the femur 56 bycontinuing to extend the drill bit through the tibial tunnel 52 and intothe femur 56. The tibial tunnel 52 and the femoral tunnel 58 are boredusing techniques well known in the art which may include the use ofalignment or drill guide mechanisms in combination with a drill bit anddriver.

Once the tibial tunnel 52 is bored through the tibia 54, a pilot hole 55is bored straight through the tibia 54 parallel with the tibia plateau.Specifically, the pilot hole 55 is started at the intersection point atthe bottom of the entrance 60 and is drilled from the anterior medial toposterior lateral side utilizing a drill bit 57 driven by the drivemechanism 70. The pilot hole 55 is preferably about 2 to 3 millimetersin diameter.

Once the pilot hole 55 has been formed or bored, a counterbore 59 isformed at the anterior medial side of the tibia 54 using a counterborebit 61 and the drive mechanism 70. The counterbore bit 61 includes apilot nose 63 which engages the pilot hole 55 to accurately align thecounterbore bit 61 concentric with the pilot hole 55 and relative to theentrance opening 60. The counterbore 59 is preferably bored to a depthof about 6 to 7 millimeters which intersects with the tibial tunnel 52or entrance opening 60.

Once the counterbore 59 has been formed utilizing the counterbore bit61, the four bundle graft 78 is first secured within the femoral tunnel58 of the femur 56 using one of the many techniques known in the art.Here again, the four bundle graft 78 is preferably secured within thefemoral tunnel 58 of the femur 56 by means of the bone mulch screw, setforth in U.S. Pat. No. 5,674,224 “BONE MULCH SCREW ASSEMBLY FORENDOSTEAL FIXATION OF SOFT TISSUE GRAFTS AND METHOD FOR USING SAME”,which is hereby incorporated by reference. With the graft 78 securedwithin the femoral tunnel 58, the graft 78 extends out through thetibial tunnel 52.

The apparatus 10 is then engaged to the tibia 54 by means of a bonescrew 65 having a head 67 and the spikes 32. The graft 78 is orientedsuch that the two grafts 94 and 96 of the four bundle graft 78 passalong a first side of the bone screw 65 and two grafts 98 and 100 passalong a second side the bone screw 65 such that the pair of grafts arepositioned or guided between the bone screw 65 and the longer guidespikes 32. The apparatus 10 is initially partially engaged with only theguide spikes 32 penetrating cancellous and cortical bone of the tibia 54and the bone screw 65 partially set.

With the guide spikes 32 engaging the tibia 54, the four bundle graft 78is appropriately tensioned by pulling the four bundle graft 78 under theengagement spikes 32 along the counterbore 59 and out of an area 69defined by the relief 20 and the counterbore 59 without binding on thesidewall 16 or the counterbore 59. The two stage spikes 14 having thefirst plurality of spikes 32 of a first length and the second pluralityof spikes 36 having a second shorter length enables the apparatus 10 tobe initially secured to the tibia 54 with only the spike 32 and bonescrew 65, while allowing tensioning and guiding of the four bundle graft78.

With the four bundle graft 78 properly tensioned, generally by means ofpulling on the ends of the graft 78 extending out of the area 69 underthe relief 20, the bone screw 65 is further turned to fully seat theapparatus or washer 10 flush within the counterbore 59, as shown clearlyin FIG. 6D. Upon turning the bone screw 65, the engagement spikes 36penetrate the two grafts 94 and 96 on the first side of the bone screw65 and the two grafts 98 and 100 on the second side of the bone screw 65to maintain proper tensioning of the four bundle graft 78. the apparatusor washer 10 thus seats flush within the counterbore 59, therebyeliminating any objects extending out beyond the tibia 54. Once the bonescrew 65 has been fully secured, the ends of the grafts 94-100 may betrimmed back within the area 64.

Turning to FIGS. 7-10, an apparatus or wedge 116 for tibial fixation ofa soft tissue graft according to the teachings of another embodiment ofthe present invention is shown. In this regard, like reference numeralswill be used to refer like structures. Here again, the wedge 116 ispreferably made from a suitable biocompatible material such as titanium,stainless steel, titanium alloy, cobalt-chrome-molybdenum alloy,polymer, resorbable polymer, etc.

The wedge 116 includes a first side 118 and a second side 120. The firstside includes a plurality of parallel running teeth 122 each defined bya first vertical sidewall 124 and a second angled sidewall 126. Eachtooth 122 includes three axial or perpendicular notches 128 formed intothe tooth 122 and an edge 130. The notches 128 being perpendicular tothe teeth 122 provides additional surface area, as well as two opposedplanes in which to grab or engage the four bundle graft 78. The edge 130of each tooth 122 has a slight arcuate shape, as shown clearly in FIG.9. The second side 120 of the wedge 116 includes an arcuate shapedperiphery 132 with a threaded face 134 formed therein. The threaded face134 is operable to be threadably engaged by an interference screw,further discussed herein.

The wedge 116 further includes a first or distal end 136 and a second orproximal end 138. The distal end 136 includes a rounded nose 140 havingthe three notches 128 on the first side 118 and a V-shaped notch orgroove 142 on the second side 120. The proximal end 138 includes a pairof wings 144 defining an open region 146 which provides for clearance ofthe interference screw. The wings 144 are angled and sized such thatwhen the wedge 116 is axially inserted into the tibial tunnel 52, a face148 of the wings 144 lies substantially flush or along the same plane asthe tibia 54. The size of the wings 144 are also larger than thediameter of the tibial tunnel 52 such that the wings 144 prevent thewedge 116 from being axially inserted or drawn into the tibial tunnel 52more than a predetermined amount.

Turning to FIG. 10, a side cross-sectional view of the wedge 116 isshown having a wider or thicker distal end 136 and a thinner or narrowerproximal end 138. The threaded face 134 is also clearly shown havingindividual threads 150 formed within the arcuate periphery 132. Theorientation of the thinner proximal end 138 which gets thicker movingout to the distal end 136 compensates or is complimentary to the shapeof the interference screw utilized. This sizing also provides engagementadjustment by locating the interference screw either further in alongthe threaded face 134 near the distal end 136 or conversely locating theinterference screw back towards the proximal end 138, further discussedherein.

Referring to FIGS. 11-12, the method for tibial fixation of the softtissue graft 78 utilizing the wedge 116 will now be described. Hereagain, the soft tissue grafts are initially harvested and prepared foruse in the articular cruciate ligament (ACL) reconstruction. Once thegrafts have been harvested and prepared using known techniques, thetibial tunnel 52 is bored through the tibia 54 and into the femur 56creating the femoral tunnel 58. The four bundle graft 78 is then securedwithin the femoral tunnel 58 using the bone mulch screw described above.Once the four bundle graft 78 has been secured within the femoral tunnel58, the four bundle graft 78 is passed through the tibial tunnel 52.

With the four bundle graft 78 extending out of the tibial tunnel 52, thefour bundle graft 78 is properly tensioned by pulling on the proximalend of the four bundle graft 78. With the four bundle graft 78 properlytensioned, the wedge 116 is positioned axially in the tibial tunnel 52below the four bundle graft 78. The first side 118 having the pluralityof teeth 122 are oriented axially and adjacent to the four bundle graft78 to substantially engage and hold the four bundle graft 78 underproper tensioning against the upper or anterior side 76 of the tunnel52. An interference screw 152 having threads 154 which matingly receivethreaded face 134 is axially inserted within the tibial tunnel 52. Anoptional guide wire 156 may be utilized which passes through a bore 158.The guide wire 156 passes from the entrance opening 60 out the exitopening 62 and is used for positioning and aligning the interferencescrew 152 during axial insertion of the interference screw 152.

With the interference screw 152 properly positioned between the secondside 120 of the wedge 116 and the lower or posterior sidewall 74 of thetibial tunnel 52, a driver, such as a hex driver engages the head 162 ofthe interference screw 152 to axially drive the interference screw 152between the second side 120 and the sidewall 74. As the driver turns theinterference screw 152, the threads 154 of the interference screw 152engage the threads 150 of the threaded face 134, as well as the sidewall74, thereby causing the interference screw 152 to axially advance fromthe proximal end of the tunnel 52 to the distal end of the tunnel 52. Asthe interference screw 152 axially advances, the wings 144 prevent thewedge 116 from being axially drawn into the tibial tunnel 52 by morethan a predetermined amount, as well as maintains the preset tension onthe four bundle graft 78. As the interference screw 152 further ascendsinto the tibial tunnel 52, the teeth 122 further engage and compress thefour bundle graft 78 under the wedge compression of the interferencescrew 152. The side cross-section wedge shape of the wedge 116, as shownin FIG. 10, is complimentary to the shape of the interference screw 152,such that initial engagement of the interference screw 152 with thewedge 116 provides a substantially planer uniform force which issubstantially transverse or perpendicular to the tibial tunnel 52. Uponfurther driving the interference screw 152 within the tunnel 52, thewedge 116 will provide additional or increased compression in the distalend 136 as the interference screw 152 passes into the notched region142. The plurality of teeth 122 having the perpendicular notches 128provide a substantial surface engagement area to securely axially retainthe four bundle graft 78 under proper tensioning endoscopically. Inaddition, the enlarged surface area distributes the tensioning forcemore uniformly over the graft 78. Still further, by providing asubstantially non-moving engagement member against the graft 78, thisreduces the possibility that the graft 78 may be frayed, slip or cut.

Referring now to FIGS. 13-15, a proximal end 164 of a wedge 166according to the teachings of another embodiment of the presentinvention is shown. In this regard like reference numerals will be usedto refer to similar structures. It should be noted that the distal endof the wedge 166 is the same as the distal end 136 of wedge 116 and theonly modification here is to the proximal end 164. In this regard, theproximal end 164 does not include a pair of wings 144 but includes ordefines a pair of notched regions 168 which are operable to be engagedby an endotibial plate grasper 172, shown in FIG. 16, and furtherdiscussed herein. The notches or grasper slots 168 are V-shaped anddefined by a bevelled or rounded end 170 of the wedge 166.

The endotibial plate grasper 172 includes complementary tines or tips174 which engage the notches 168 to firmly grasp and secure the plate176. Set back from the tips 174 and adjacent thereto is an alignmentplate 176 sized to be larger than the tibial tunnel 52 and angledsubstantially similar to the wings 144. The plate grasper or instrument172 further includes a handle 178 having a locking mechanism 180 suchthat the plate 166 can be engaged by the tips 174 and locked or heldsecured by the locking mechanism 180.

The method for utilizing the wedge 166 in combination with the plategrasper 172 will now be described with reference to FIG. 17. Once again,the soft tissue grafts are harvested and prepared using knowntechniques. The tibial tunnel 52 and the femoral tunnel 58 are boredthrough both the tibia 54 and the femur 56. The four bundle graft 78 isagain secured within the femoral tunnel 58 using known techniques suchas the bone mulch screw identified above.

The four bundle graft 78 extending through the tibial tunnel 52 is thenproperly tensioned. Once the four bundle graft 78 is properly tensioned,the instrument 172 engages the notches 168 of the wedge 166, via thetips 174. With the wedge 166 being firmly held by the instrument 172,via the locking mechanism 180, the wedge 166 is axially inserted intothe tibial tunnel 52 until the plates 176 engage the entrance opening 60of the tibial tunnel 52. Here again, the teeth 122 transversely engagethe four bundle graft 78, as the interference screw 152 is axiallydriven into the tibial tunnel 52. The plate 176 prohibits the wedge 166from being axially drawn into the tibial tunnel 52 by more than apredetermined amount thereby maintaining proper graft tensioning, aswell as maintaining the proper alignment of the wedge 166 against thefour bundle graft 78. Once the four bundle graft 78 is axially securedwithin the tibial tunnel 52, the plate grasper 172 is removed from thewedge 166, thereby providing a properly tensioned and endoscopicallyaxially secured four bundle graft 78.

Turning to FIG. 18, as well as referring to FIGS. 1-3, an apparatus 200for tibial fixation of a soft tissue graft according to the teachings ofa first preferred embodiment of the present invention is shown. Theapparatus or washer 200 is substantially similar to the apparatus 10, asshown in FIGS. 1-3, and in this regard, like reference numerals will beused to identify like structures. Here again, the fixation apparatus orwasher 200 includes the cylindrical body 12 and the plurality of spikes14. The cylindrical body 12 includes the cylindrical sidewall 16 havingthe bevelled or rounded edges 18 and the substantially flat planarrelief face 20 formed into a portion of the cylindrical sidewall 16. Thebody 12 further includes the internal bore 22 which includes a threadedinternal sidewall 202 which is able to be threadably secured to acombination implant and guide instrument, further discussed herein. Thetop 26 of the body also includes the concentric counterbore 28 and thebottom 30 of the body 12 includes the plurality of spikes 14 extendingout from the second side 30. Here again, the washer 200 may be made fromany suitable bio-compatible material and may also be made in variousdifferent sizes, as with the washer 10, depending on the patient's needsand the doctor's requirements.

Referring to FIG. 19, a counterbore guide 204 is shown for use inpreparing of a substantially perpendicular counterbore relative to atibial tunnel formed in a tibia, further discussed herein. Thecounterbore guide 204 includes a substantially cylindrical body 206having a circular handle 208 with a planar region 210. Extendingsubstantially perpendicular from the cylindrical body 206 is apositioning bar 212 which is secured to the cylindrical body 206 by wayof a groove formed in the lower portion of the cylindrical body 206 anda weld. The positioning bar 212 is utilized to engage the medial cortexof the tibia at two points to provide a predetermined insertion lengthof the counterbore guide 204 into the tibial tunnel. Set back from thepositioning bar 212 is a tubular guide bushing 214. The guide bushing214 includes a cylindrical bore 216 which mates and is concentric with abore 218 defined by the cylindrical body 206. The guide bushing 214 issecured substantially perpendicular to the cylindrical body 206 by meansof a weld or any other appropriate fixation. The guide bushing 214engages the opening of the tibial tunnel and is operable to permit aguide bore to be formed substantially perpendicular to the tibialtunnel, further discussed herein.

A combination implant and guide instrument 220 which is operable toimplant the washer 200, as well as perform other purposes, is shown inFIGS. 20 and 21. The instrument 220 includes a first awl portion 222 anda second guide portion 224. The first awl portion 222 includes acylindrically shaped handle 226 having notched regions 228 and anelongated neck 230. Extending substantially concentric with the handle226 is an elongated cylindrical awl or guide shaft 232 having a distalpoint or tip 234. The first portion 222 also includes a threadedconnector member 236 which is operable to threadably engage the secondportion 224, further discussed herein.

The second guide portion 224 also includes a substantially cylindricalhandle 238 having notches 240 and an elongated neck 242. Extending fromthe substantially cylindrical neck 242 is a circular impact plate 244.The impact plate 244 may either be formed integrally with the guidemember 224 or may be formed as a separate annular member having aninternal threaded bore which is threadably received upon a threadedconnection member 246. The threaded connection member 246 extends outbeyond the impact plate 244 and is operable to threadably engagethreaded sidewall 202 of the fixation apparatus 200, further discussedherein. Passing concentrically through the drill guide 224 is acenterbore 248 having an internal threaded sidewall portion 250. Thebore 248 is operable to receive the guide shaft 232, while the threadedsidewall 250 threadably engages the threaded connection member 236. Inthis way, the first portion 222 and the second portion 224 form thecombination implant and guide instrument 220 which is operable toperform several functions during the implantation procedure.

Turning to FIGS. 22A-22D, a first preferred method for tibial fixationof a soft tissue graft will now be described. In this regard, likereference numerals will be used to identify like structures, asdescribed in the method set forth in FIGS. 5A-5E. Initially, soft tissuegrafts are harvested and prepared using known techniques and aspreviously described. Once the soft tissue grafts have been harvestedand prepared, tunnel or hole placement is performed, as also previouslydescribed. Specifically, the tibial tunnel or bore 52 is drilled throughthe tibia 54 and into the femur 56 creating the femoral tunnel 58.

Once the tibial tunnel 52 is bored through the tibia 54, the cylindricalbody 206 of the counterbore guide 204 is axially slid into the entranceopening 60 of the tibial tunnel 52. The counterbore guide 204 isslidably advanced into the tibial tunnel 52 until the positioning bar212 engages and is flush against the medial cortex of the tibial 54along two contact points. This will align the guide bushing 214substantially adjacent and in contact with the anterior edge 64 orsuperior portion of the entrance opening 60 of the tibial tunnel 52.This provides for a stable three point contact at the entrance opening60 to the tibial tunnel 52. Additionally, the planar region 210 of thehandle 208 acts as a site mechanism with the guide bushing 214 to insureproper rotation of the counterbore guide 204 in the tibial tunnel 52.

Once the counterbore guide 204 is properly positioned within the tibialtunnel 52 and held by the handle 208, the substantially three pointcontact should be made within the oval opening 60 by way of thepositioning bar 212 and the guide bushing 214. This substantially alignsthe guide bushing 214 substantially perpendicular to the tibial tunnel52. Once aligned and set, the first portion 222 of the combinationimplant and guide instrument 220 is employed. In this regard, the awl orguide shaft 232 is slidably received within the bore 216 of the guidebushing 214 until the point 234 engages the posterior wall 74 of thetibial tunnel 52. Once engaged, the first portion 222 is impacted bystriking the handle 226 with a mallet or other appropriate impactdevice. The shaft 232 is impacted until the tip 234 is substantiallyadjacent to the posterior side of the tibia 54. This forms a guide bore254 used to guide the combination implant and guide instrument 220 and acounterbore bit, further discussed herein. Once the guide bore 254 isformed, the guide shaft 232 is removed from the guide bushing 214 andthe counterbore guide 204 is slidably removed from the tibial tunnel 52.This provides a substantially perpendicular guide bore 254 relative tothe tibial tunnel 52.

After the guide bore 254 is formed with the punch 222, the counterbore66 is formed substantially perpendicular to the tibial tunnel 52 using acounterbore bit 256 and the drive mechanism 70, as shown in FIG. 22B.The counterbore bit 256 includes a substantially cylindrical centeringnose 258 which rotatably engages the guide bore 254. Here again, thecounterbore 66 is preferably bored to remove the anterior edge 64 or thesuperior portion of the entrance opening 60 to provide a substantiallyperpendicular counterbore 66. In other words, with the guide orcentering nose 258 guided, via the guide bore 254, the counterbore bit256 is perpendicular to the posterior wall 74 of the tibial tunnel 52and is advanced to the posterior wall 74.

Once the counterbore 66 has been formed utilizing the counterbore bit256, the four bundle graft 78 is first secured within the femoral tunnel58 of the femur 56 using one of the many techniques known in the art andas previously described herein. Once the graft 78 is secured within thefemoral tunnel 58, the graft 78 extends out through the tibial tunnel52. The second portion 224 of the combination implant and guideinstrument 220 is then threadably secured to the first portion 222 byway of the threaded sidewall 250 and the threaded connection member 236.Once assembled, the shaft 232 extends out beyond the impact plate 244 byabout 1.25 inches. The threaded connection member 246 is then threadablyengaged with the threaded sidewall 202 of the apparatus 200 to removablysecure the apparatus 200 to the impact plate 244. As the apparatus 200is threadably secured to the threaded member 246, the impact plate 244seats within the spherical counterbore 28 and the shaft 232 extends outthe center of the fixation apparatus 200.

The shaft 232 also extends out beyond the spikes 32 to permit guiding ofthe apparatus 200 substantially perpendicular to the tibial tunnel 52.Specifically, the planar relief face 20 of the apparatus 200 is firstpositioned inferior to the counterbore 66. The shaft 232 is thenslidably engaged within the guide bore 254 until the spikes 32 engagethe posterior portion 74 of the tibial tunnel 52. At this point, thegraft 78 is oriented, as shown in FIG. 5E where the two grafts 94 and 96of four bundle graft 78 pass along a first side of the shaft 232 and twografts 98 and 100 pass along a second side of the shaft 232 such thateach pair of grafts are positioned or guided between the longer guidespikes 32 and the guide shaft 232.

Here again, the fixation apparatus 200 is initially engaged with onlythe guide spikes 32 penetrating cancellous bone of the tibia 54 with therelief face 20 directed toward the entrance opening 60. Once the guidespikes 32 engage the tibial 54, the four bundle graft 78 isappropriately tensioned by pulling the four bundle graft 78 under theengagement spikes 36 within the counterbore 66 and out the area 102defined by the relief 20 (see FIG. 5E) without binding on the sidewall16 or the counterbore 66. Once proper tension is achieved on the fourbundle graft 78, the apparatus 200 is fully implanted or nested withinthe counterbore 66 by striking the handle 226 with a mallet or otherappropriate driving device, as shown clearly in FIG. 22C. Upon seatingthe apparatus 200, the engagement spikes 36 penetrate the two grafts 94and 96 on the first side of the guide shaft 232 at multiple sights andthe two grafts 98 and 100 on the second side of the guide shaft 232 tomaintain the proper tensioning of the four bundle graft 78. This seatsthe fixation apparatus 200 flushly within the counterbore 66, therebyeliminating any objects extending out beyond the tibia 54.

Once the apparatus 200 is fully nested within the counterbore 66 or theposterior wall 74 of the tibial tunnel 52, the first portion 222 of thecombination implant and guide instrument 220 is threadably disengagedfrom the second portion 224. With the second portion 224 stillthreadably secured to the apparatus 200, this provides a guidesubstantially perpendicular to the tibial tunnel 52, via the bore 248,passing through the second portion 224. A drill bit 260 driven by thedriver 70 is then guided through the bore 248, between the grafts 94 and96 and 98 and 100 and down through the guide bore 254, shown in FIG.22D. The drill bit 260 enlarges the guide bore 254 for receipt of thelow profile compression screw 108, shown in FIG. 5D. Once the bore 262is drilled into the tibia 54 to the posterior cortex region, the bore262 may then be tapped with an appropriate tap, should this be desired.The length of the screw 108 is then determined using any conventionalmeasuring instrument. Once selected, the low profile compression screw108 is passed through the apparatus 200 and threaded into the bore 262to complete the fixation of the apparatus 200.

Referring now to FIG. 23, a second preferred embodiment of thecounterbore guide 204′ is shown. In this regard, like reference numeralswill be used to identify like structures with respect to the counterboreguide 204. The counterbore guide 204′ is substantially the same as thecounterbore guide 204, except that the counterbore guide 204′ includesor defines a slot 264 passing through the cylindrical body 206 and aslot 266 passing through the guide bushing 214. Each slot 264 and 266enables a guide wire, further discussed herein, to be slidably passedthrough each slot and out from the counterbore guide 204′.

A second combination implant and guide instrument 270 according to theteachings of a second preferred embodiment of the present invention isshown in FIG. 24, which may be used in place of the instrument 220. Theinstrument 270 includes a substantially cylindrical handle 272 havingnotches 274 and an elongated tubular shaft 276. The shaft 276 defines asubstantially cylindrical bore 278 passing axially through the shaft276. The bore 278 includes a threaded sidewall portion 280 which isoperable to be threadably engaged by a threaded connector member 282extending from the handle 272. Positioned at the end of the shaft 276opposite the handle 272 is a circular impact head or plate 284 having asubstantially spherical impact face 286 and a threaded connection member288. The implant plate 284 may be a separate member threaded on theconnection member 288 or integral with the shaft 276. The connectionmember 288 threadably engages the threaded sidewall 202 of the apparatus200, while the spherical face 286 nestingly rests within the counterbore28.

A second preferred method for tibial fixation of a soft tissue graftwhich employs the counterbore guide 204′ and the combination implant andguide instrument 270 is shown in FIGS. 25A-25C. Here again, likereference numerals will be used to identify like structures. Once thegraft 78 has been harvested and prepared using the known techniques, thetibial tunnel 52 is again drilled through the tibia 54 and into thefemur 56 to form the femoral tunnel 58. As shown in FIG. 25A, thecounterbore guide 204′ is axially slid into the entrance opening 60 ofthe tibial tunnel 52 with the positioning bar 212 and the guide bushing214 coming to rest against the opening 60. Once properly positioned, aconventional guide wire 290 is passed through the guide bushing 214 andfixedly driven into the tibia 54, via the driver 70 to create a guidebox that secures the guide wire 290. Once secured to the tibia 54, thecounterbore guide 204′ is slidably removed from the tibial tunnel 52 asthe guide wire 290 remains in place substantially perpendicular to thetibial tunnel 52. As the counterbore guide 204′ is slidably removed fromthe tibial tunnel 52, the guide wire 290 exits through the slots 266 and264, respectively.

The counterbore 66 is again formed by the use of a counterbore bit 292which is driven by the driver 70. The counterbore bit 292 includes anelongated shaft 294 and includes and defines a cylindrical bore 296passing through the entire counterbore bit 292. To insure that thecounterbore bit 292 is aligned substantially perpendicular to the tibialtunnel 52, the counterbore bit 292 is slidably inserted over the guidewire 290 and rotatably advanced to form the counterbore 66, shownclearly in 25B, as the guide wire 290 passes up through the counterborebit 292.

Once the counterbore 66 is formed, the combination implant and guideinstrument 270 threadably receives the apparatus 200, via the threadedsidewall 202 and the threaded connector member 288. The impact face 284nestingly seats within the counterbore 28 as the apparatus 200threadably engages the threaded connector member 288. The apparatus 200is again aligned substantially perpendicular to the tibial tunnel 52 bymeans of the guide wire 290. In this regard, the guide wire 290 extendsthrough the apparatus 200 and into the bore 278 of the instrument 270 sothat the instrument 270 is slidably guided by the guide wire 290substantially perpendicular to the tibial tunnel 52. Here again, thespikes 32 are first set in the posterior wall 74 of the tibial tunnel 52with the planar face 20 facing inferiorly. The graft 78 is againtensioned as previously described and the apparatus 200 is then fullyseated by impacting the handle 272 with a mallet or other appropriatedevice.

Once the apparatus 200 is fully seated within the counterbore 66, thehandle 274 is threadably removed from the shaft 276, via the threadedconnector member 282, thereby exposing the bore 278. With the drillguide shaft 276 still threadably secured to the apparatus 200, the bore278 guides the drill bit 260 driven by the driver 70, as shown similarlyin FIG. 22D to form the enlarged bore 262. The low profile compressionscrew 108 is then inserted into the bore 262 to complete the fixation ofthe apparatus 200 within the counterbore 66.

The combination implant and guide instrument 220 performs at least threefunctions consisting of forming the guide bore 254, implanting thefixation apparatus 200 and guiding the drill bit 260. The combinationimplant and guide instrument 270 performs at least two functionsincluding implanting the fixation apparatus 200 and guiding the drillbit 260. Accordingly, use of the combination implant and guideinstrument 220 or 270 reduces the amount of separate instrumentationrequired to secure the soft tissue graft 78, as well as reduces oreliminates additional steps in the technique. Additionally, bymaintaining one portion of each instrument 220 or 270 secured to thefixation apparatus 200 during the implant procedure, further accuracy isachieved. Further accuracy is also achieved by use of the guide shaft232 or the guide wire 290 to maintain and form the counterbore 66substantially perpendicular to the tibial tunnel 52, as well as insurethat the apparatus 200 is impacted substantially perpendicular to thetibial tunnel 52.

The foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. One skilled in the art willreadily recognize from such discussion, and from the accompanyingdrawings and claims, that various changes, modifications and variationscan be made therein without departing from the spirit and scope of theinvention as defined in the following claims.

What is claimed is:
 1. An apparatus for fixation of a soft tissue graft, said apparatus comprising: a body having a first side and a second side, said body being substantially cylindrical and including a substantially cylindrical sidewall having a diameter; a first plurality of spikes extending from said second side of said body, each of said first plurality of spikes having a first length and a first pointed end; and a second plurality of spikes extending from said second side of said body, each of said second plurality of spikes having a second length and a second pointed end, said first length being longer than said second length, wherein said first plurality of spikes are operable to engage and pierce the bone with said first pointed ends without said second plurality of spikes substantially engaging the soft tissue graft to permit proper tensioning of the soft tissue graft, and wherein said second plurality of spikes are operable to engage and pierce the soft tissue graft with said second pointed ends.
 2. The apparatus as defined in claim 1 wherein said substantially cylindrical body includes a substantially planar relief formed into a portion of said substantially cylindrical sidewall.
 3. The apparatus as defined in claim 2 wherein said substantially cylindrical body is nested within a counterbore and said substantially planar relief permits said soft tissue graft to exit the counterbore without binding on said substantially cylindrical sidewall and said counterbore.
 4. The apparatus as defined in claim 1 wherein said substantially cylindrical body defines an internal bore and a concentric counterbore formed within the first side of said substantially cylindrical body operable to receive a screw having a head.
 5. The apparatus as defined in claim 4 wherein said internal bore includes a threaded internal sidewall.
 6. The apparatus as defined in claim 1 wherein each of said plurality of spikes has a first diameter and wherein each of said second plurality of spikes has a second diameter, said first diameter being larger than said second diameter.
 7. The apparatus as defined in claim 1 wherein said first plurality of spikes are positioned concentrically about said substantially cylindrical body and retains and guides the soft tissue graft under said second plurality of spikes that are positioned between said first plurality of spikes and an internal bore, whereby said second plurality of spikes are operable to pierce said soft tissue graft at a plurality of sites.
 8. The apparatus as defined in claim 1 further comprising a counterbore drill guide having a substantially cylindrical body defining a notched region with a centering hole operable to receive a counterbore bit.
 9. The apparatus as defined in claim 1 further comprising an impactor having a complimentary face which mates with said first side of said substantially cylindrical body and including an edge guide operable to engage a said substantially planar relief formed into a portion of a substantially cylindrical sidewall of said substantially cylindrical body.
 10. The apparatus as defined in claim 9 wherein said impactor further includes a guide post which is operable to be received within an internal bore defined by said substantially cylindrical body.
 11. An apparatus for fixation of a soft tissue graft within a counterbore formed into a bone, said apparatus comprising: a body having a first side and a second side, said body being substantially cylindrical and including a substantially cylindrical sidewall having a first diameter and a substantially planar relief formed into a portion of said substantially cylindrical sidewall; and a plurality of spikes extending from said second side of said substantially cylindrical body, said plurality of spikes operable to engage the bone, whereby said substantially planar relief is operable to permit said substantially cylindrical body to be flushly received within the counterbore and permit the soft tissue graft to exit the counterbore without substantially binding on said substantially cylindrical sidewall of said substantially cylindrical body and the counterbore.
 12. The apparatus as defined in claim 11 wherein said plurality of spikes includes a first plurality of spikes each having a first pointed end and a second plurality of spikes each having a second pointed end, each of said first plurality of spikes having a first length and each of said second plurality of spikes having a second length, said first length being longer than said second length.
 13. The apparatus as defined in claim 12 wherein each of said first plurality of spikes has a first diameter and each of said second plurality of spikes has a second diameter, said first diameter being larger than said second diameter.
 14. The apparatus as defined in claim 13 wherein said substantially cylindrical body defines an internal bore and a concentric counterbore formed in said first side of said substantially cylindrical body operable to receive a screw having a head, whereby said first plurality of spikes retains said soft tissue graft between said first plurality of spikes prior to engaging said soft tissue graft with said second plurality of spikes.
 15. An apparatus for fixation of a soft tissue graft, said apparatus comprising: a body having a first side and a second side, said body being substantially cylindrical and including a substantially cylindrical sidewall having a diameter; a first plurality of spikes extending from said second side of said body, each of said first plurality of spikes having a first length; and a second plurality of spikes extending from said second side of said body, each of said second plurality of spikes having a second length, said first length being longer than said second length, wherein said first plurality of spikes are operable to engage the bone without said second plurality of spikes substantially engaging the soft tissue graft to permit proper tensioning of the soft tissue graft, wherein said first plurality of spikes are positioned concentrically about said substantially cylindrical body at a first radius and said second plurality of spikes are positioned between said first plurality of spikes and an internal bore.
 16. The apparatus as defined in claim 11 further comprising a counterbore drill guide having a substantially cylindrical body defining a notched region with a centering hole operable to receive a counterbore bit.
 17. The apparatus as defined in claim 11 further comprising an impactor having a complimentary face which mates with said first side of said body, an edge guide operable to engage said substantially planar relief formed into a portion of said substantially cylindrical sidewall of said substantially cylindrical body, and a guide post which is operable to be received within an internal bore defined by said body. 